Method and apparatus for controlling FCC effluent with near-infrared spectroscopy

ABSTRACT

On-line controlling of catalytic cracking processing is provided which uses near infrared (NIR) analysis to characterize FCC effluent and the resulting characterization thereof. The NIR results can be used in FCC software to control on-line unit yields and qualities.

TECHNICAL FIELD

This invention relates to controlling FCC reactor effluent yields withnear infrared spectroscopy. More specifically, the present inventionrelates to the use of NIR to conduct RMS testing on-line.

BACKGROUND OF THE INVENTION

Near IR spectroscopy has been used in the past to determine physicalproperties of petroleum hydrocarbon mixtures. This includes using theNIR results to control refinery processes including gasoline blendersand catalytic reforming units. It is a quick, non-destructive analyticaltechnique that is correlated to primary test methods using amultivariate regression analysis algorithm such as partial least squaresor multiple linear regression. It has been used in a laboratory topredict properties of refinery blender streams and finished gasoline anddiesel fuel.

Optimization, design and control of catalytic cracking process units allbenefit from kinetic models which describe the conversion of feeds toproducts. In order to properly describe the effects of changes in feedcomposition, such models require descriptions of the feed in terms ofconstituents which undergo similar chemical reactions in the crackingunit. For design and optimization studies, a protocol which involvesoff-line feed analysis taking weeks or even months to provide a feeddescription.

A Near IR (NIR) spectrophotometer can be used to collect spectra onFluid Catalytic Cracking (FCC) feedstocks and products. When seeking tooptimize the performance of the FCC unit, it is critical to accuratelydefine the operation as it exists before decisions regarding significantprocess or equipment changes are finalized. This involves careful andprecise measurement of FCC yields as well as key process parametersincluding feed quality; feed rate, FCC operating conditions and FCCproduct properties. NIR represents a tool to accurately define feedstockquality and reactor effluent yields to facilitate FCC unit optimization.

Reaction Mixing Sampling (RMS) is a technique that has been developed bythe refining industry to measure reactor effluent yields from a FluidCatalytic Cracking (FCC) unit. NIR is a new tool that can be applied onthe reactor vapor line of a commercial FCC unit to measure yieldson-line.

Other objects and advantages of the present invention will becomeapparent to those skilled in the art upon a review of the followingdetailed description of the preferred embodiments and the accompanyingdrawings.

SUMMARY OF THE INVENTION

The novel of NIR is the ability to conduct RMS testing on-line. The NIRwill provide a near instantaneous prediction of unit yields and does notrequire the physical collection of samples for distillation and analysisby an outside laboratory. This facilitates all the benefits of thecurrent RMS objectives and allows for more frequent optimization.

In order to verify that feed quality remains constant over the durationof the test run period, various methods were developed for thecollection of reaction effluent samples directly from the overhead linefrom the FCC reactor vessel to the fractionator. One such method isreferred to as the FCC Reaction Mix Sampling (RMS) test run.

The collection of effluent sample from the overhead line essentiallydecouples the reactor-regenerator section from the main fractionator,often making it unnecessary to line out the fractionator and gas plantbefore taking the next sequential set of RMS samples. Typically, lessthan one hour of equilibration time is required between making anadjustment in FCC operating conditions and the subsequent collection ofa reactor effluent sample. If FCC light cycle oil (LCO), heavy cycle oil(HCO) or decanted oil is recycled back to the riser, additional time maybe required to stabilize the fractionator operation, although it isstill not necessary to line out the towers in the FCC gas plant.

The present invention provides a process for controlling on-line FCCeffluent exhibiting absorption in the near infrared (NIR) region. Theprocess steps include:

-   -   a) measuring absorbances of the effluent using a spectrometer        measuring absorbances at wavelengths within the range of about        780-4000 nm, e.g., 780-2500 nm, and outputting an emitted signal        indicative of said absorbance;    -   b) subjecting the NIR spectrometer signal to a mathematical        treatment (e.g. derivative, smooth, baseline correction) of the        emitted signal.    -   c) processing the emitted signal or the mathematical treatment        using a defined model to determine the chemical or physical        properties of the effluent and outputting a processed signal;        and    -   d) controlling on-line in response to the processed signal, at        least one parameter of a FCC process generating the effluent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an FCC unit comprising a reactor and aregenerator showing the control system of the present invention in placefor operating that FCC unit.

FIG. 2 is a Table which shows samples, including hydrotreater chargesand products and FCC feeds used to control on-line weight percents ofeach hydrocarbon class.

FIG. 3 is an on-line, FCC model tuning with RMS data.

DETAILED DESCRIPTION OF THE INVENTION

The process of this invention verifies that feed quality remainsconstant over the duration of the test run period, various methods weredeveloped for the collection of reaction effluent samples directly fromthe overhead line from the FCC reactor vessel to the fractionator. Onesuch method is referred to as the FCC Reaction Mix Sampling (RMS) testrun.

To perform RMS testing, a small diameter pipe probe is inserted into anavailable tap at some point along the reactor overhead transfer line. Asmall stream of reaction effluent vapor is withdrawn through the pipeprobe and into an air-cooled condenser, where the mixture is cooled to atemperature that is only 20° F. to 30° F. above ambient. The cooledreaction effluent now consists of two-phase flow with the LCO, bottomsand most of the FCC gasoline condensed to the liquid phase. Thistwo-phase total reaction mixture flows from the condensing coil intospecialized 90 liter sampling bags. The bags in a laboratory and arethen analyzed for the information required to calculate FCC unit yields.

The collection of effluent sample from the overhead line essentiallydecouples the reactor-regenerator section from the main fractionator,often making it unnecessary to line out the fractionator and gas plantbefore taking the next sequential set of RMS samples. Typically, lessthan one hour of equilibration time is required between making anadjustment in FCC operating conditions and the subsequent collection ofa rector effluent sample. If FCC light cycle oil (LCO), heavy cycle oil(HCO) or decanted oil is recycled back to the riser, additional time maybe required to stabilize the fractionator operation, although it isstill not necessary to line out the towers in the FCC gas plant.

Petroleum refining is a never-ending quest for higher throughputs,better yields, higher onstream factors, improved reliability, cheaperfeedstocks and cleaner fuels. At the heart of this effort is the fluidcatalytic cracking or FCC process. The FCC process is undergoing wavesof evolutionary change with improvements in feed injection, risertermination, catalyst stripping, spent catalyst distribution, crackingcatalyst and additive performance, emissions reduction and FCC naphthasulfur reduction technology.

When seeking to optimize the performance of the FCC unit, it is criticalto accurately define the operation as it exists before decisionsregarding significant process or equipment changes are finalized. Thisinvolves careful and precise measurement of FCC yields as well as keyprocess parameters including feed quality; feed rate, FCC operatingconditions and FCC product properties.

We use a Near IR (NIR) spectrophotometer to collect spectra on FluidCatalytic Cracking (FCC) feedstocks and products. Improved FCC kineticmodels and computer simulations have resulted in use of an optimizerprogram to select operating parameters of the FCC unit to maximizeprocessing against unit constraints. This is typically done off-lineusing a discrete set of data. NIR measurement of feed and productsenables this process to be done on-line allowing the process to operateat maximum efficiency.

Once an FCC reaction effluent sample is collected and the FCC operatingvariables are subsequently adjusted to the next desired set of operatingconditions, less than 60 minutes are typically required for thereactor-regenerator operation to reach a new equilibrium state. For awell-coordinated series of FCC test runs, it is possible to collectreaction effluent samples at as many as four different sets of FCCoperating conditions in an eight-hour shift. This creates theopportunity to eliminate feedstock variation and the data adjustmentsthat will ultimately have to be made in order to directly compare testrun results. The use of reaction effluent testing makes it moreconvenient to complete the following types of variable studies and tointerpret the results of changing process variables on FCC yields.

-   -   Effect of riser outlet temperature    -   Effect of feed temperature    -   Effect of feed rate    -   Effect of dispersion steam rate    -   Effect of extraneous light feed streams such as process naphthas        and middle distillates.    -   Effect of percentage of deasphalted oil, atmospheric and vacuum        reside in feed blend.    -   Effect of lift gas or riser lift steam rate.

FCC PROCESS

Catalytic cracking is the backbone of many refineries. It converts heavyfeeds (600°-1050° F.) such as atmospheric gas oil, vacuum gas oil, cokergas oil, lube extracts, and slop streams, into lighter products such aslight gases, olefins, gasoline, distillate and coke, by catalyticallycracking large molecules into smaller molecules. Catalytic crackingoperates at low pressures (15 to 30 psig), in the absence of externallysupplied H₂, in contrast to hydrocracking, in which H₂ is added duringthe cracking step. Catalytic cracking is inherently safe as it operateswith very little oil actually in inventory during the cracking process.

FCC feedstocks include that fraction of crude oil which boils at 650° to1000° F., such fractions being relatively free of coke precursors andheavy metal contamination. Such feedstock, known as “vacuum gas oil”(VGO) is generally prepared from crude oil by distilling off thefractions boiling below 650° F. at atmospheric pressure and thenseparating by further vacuum distillation from the heavier fractions acut boiling between 650° F. and 900° to 1025° F. The fractions boilingabove 900° to 1025° F. are normally employed for a variety of otherpurposes, such as asphalt, residual fuel oil, #6 fuel oil, or marineBunker C fuel oil. However, some of these higher boiling cuts can beused as feedstocks in conjunction with FCC processes which utilizecarbo-metallic oils by Reduced Crude Conversion (RCC) using aprogressive flow type reactor having an elongated reaction chamber.

FIG. 1 is a schematic diagram of an FCC unit comprising a reactor and aregenerator showing the control system of the present invention in placefor operating that FCC unit.

FIG. 1 shows feed 20 is heated by fired heater 22 which is heated by gasburner 24, fuel to which is controlled by automatic valve 26. Justbefore the fuel enters the fired heater 22, a sample 30 is withdrawn andconducted by tubing into NIR unit 32. In an alternate embodiment (notshown), a fiber optic probe inserted directly into the feed line beforefired heater 22 can obviate the need for withdrawing sample.

NIR unit 32 can be located on-line and can include a sample conditioningmeans for controlling the temperature, and for extracting bubbles anddirt from the sample. The NIR unit also comprises a spectrometer meanswhich may be a spectrometer of the NIR, Fourier Transform Near Infrared(FTNIR), Fourier Transform Infrared (FTIR), or Infrared (IR) type,ruggedized for process service and operated in a temperature-controlled,explosion-proof cabinet. A photometer with present optical filtersmoving successively into position, can be used as a special type ofspectrometer.

NIR spectrometer 32 outputs a signal to computer 40 which preferablytakes a derivative of the signal from the spectrometer, and subjects itto a defined model to generate the properties of interest. The model isoptionally derived from signals obtained from NIR measurement ofcracking products.

In operation, the FCCU operates conventionally with feed being fired inheater 22 entering riser 50, together with catalyst descending throughthe catalyst return line 52 and entering riser 50. The vaporizedproducts ascend riser 50 and are recovered in the reactor by cyclone 54with product vapors 58 exiting to the main column for fractionation andrecovery of various products. Naphtha product can be recycled throughline 60. Spent catalyst descends from the reactor through lines 64 intothe regenerator 68 and contacts air to burn off carbon and produce fluegas which exits through flue cyclone 72 and flue gas line 72. Variousother components are shown, but not described. For example, computer 40controls catalyst cooler 76 through catalyst temperature line 78.Injection water line 80 also is shown.

Optionally or alternatively, a second sample taken from the reactorproduct vapors 58 can be input through line 59 to spectrometer 32,permitting the spectrometer to analyze the products so that computer 40can compare the group type analysis of the products against the optimumproducts slate desired for maximum economy.

EXAMPLE 1

Different feedstocks will result in different yields from the FCCprocess. If the unit is operating against a constraint, the process willneed to adjust to avoid exceeding an equipment limitation. Typicalprocess variables include feed rate, reactor temperature, feed preheatand pressure. The process response from each of the variables isnon-linear. The optimum set of conditions to maximize profitability tounit constraints will typically vary depending upon the feed quality.The following is an example of different operating conditions requiredto maximize profitability for a change in feed:

New Feed New Feed New Feed with with Only with Only Normal MultivariableRate ROT Operation Optimization Varied Varied Feed Properties API 24.621.8 21.8 21.8 UOP K 11.69 11.77 11.77 11.77 Concarbon (%) 0.15 0.590.59 0.59 Nitrogen (ppm) 1150 162 162 162 Sulfur (%) 0.34 0.55 0.55 0.551-ring Aromatics 35 29 29 29 (%) 2-ring Aromatics 34 26 26 26 (%) 3-ringAromatics 17 25 25 25 (%) 4-ring 14 20 20 20 Aromatics+(%) ProcessConditions Feed Rate 100 95.3 83.8 100 (% Capacity) Reactor 1010 9921006 986 Temperature (F.) Reactor Pressue 34.7 33.6 32.3 34.2 (psig)Equipment Constraints Wet Gas 100 100 100 100 Compressor (%) Main AirBlower 100 90 84 94 (%) Yields Conversion (lv %) 77.55 74.33 76.83 73.59

The results show the application of RTO using NIR allows the FCC processto automatically adjust processing conditions to maximize processing asfeedstock quality changes. Without the feedstock quality via NIR andRTO, the process will operate at a non-optimum condition until a modeloptimizer can be run and the results implemented. Conventional practiceis limited to use of APC where typically only 1 variable an bemanipulated to push the unit against constraints. On-line RTO chooses aset of operating conditions to maximize value.

EXAMPLE 2

FIG. 2 is a Table which shows samples, including hydrotreater chargersand products and FCC feeds used to control weight percents of eachhydrocarbon class.

Two hundred fifty samples, including hydrotreater charges and productsand FCC feeds were used to create a PLS model for predicting weightpercents of each hydrocarbon class. The samples were analyzed using theonline NIR. Wavelengths were chosen for each group and a summary appearsin FIG. 2.

EXAMPLE 3 The Effect or Riser Temperature

One of the most common types of process variable studies completed viathe use of reaction effluent testing is the impact of riser outlettemperature on FCC reactor yields. This is one of the most fundamentalsets of data required to optimize the performance of the FCC unit. Table1 contains results from a riser temperature test runs series. For thisstudy, reactor effluent samples were collected at three different riseroutlet temperatures, with the maximum riser temperature constrained bythe ability to handle gas volumes in the FCC gas plant.

TABLE 1 Effect of Riser Outlet Temperature on FCC Product Yields RiserOutlet Temperature: F. +15° F. Base −18° F. Unit Conversion: Volume % FF+1.4 Base −3.2 Gasoline Yield: Volume % −0.3 Base +0.2 Total C3 plus C4Yield: Volume % FF +1.3 Base −3.8 Ethane and Lighter Yield: Weight % FF+0.51 Base −0.63 Coke Yield: Weight % FF +0.17 Base −0.18

EXAMPLE 4 The Effect of Riser Lift Velocity

In order to truly optimize the performance of the FCC unit, it isimportant to understand the interaction of all reaction processvariables on FCC product yields. Recently, reaction effluent testing wasused to explore the impact of riser lift steam rate on unit yields. Inthis case riser steam rate was increased by 165% with riser velocityincreasing from ˜10 fps to ˜17 fps. Increasing the rate of lift steaminjection at constant feed rate results in the following effects.

The heat requirement on the reactor side increases because of the needto heat the steam from the injection temperature to the riser outlettemperature. This results in a call for increased catalyst circulationto maintain the riser outlet temperature constant.

1. The increased catalyst-to-oil ratio results in a greater degree ofcatalytic cracking relative to thermal cracking. This is evident becauseof the higher yield of catalytically racked gasoline and the lower yieldof ethane and lighter gas, which is generally the result of thermalcracking in the riser and reactor.

2. There is a reduction in the feed residence time in the riser becauseof the increased riser volumetric vapor flow resulting from increasedamount of riser lift steam.

3. The increased velocity creates a more uniform distribution ofcatalyst near the wall of the riser where feed is injected. Thisimproves feed contacting allowing for improved riser hydrodynamics. Thisparticular unit utilized a J-bend with modern feed nozzles.

TABLE 2 Effect of Riser Lift Steam Rate on FCC Product Yields RiserInjection Steam Rate: PPH Base  +165% Catalyst Circulation Rate: TPMBase  +4.5% Unit Conversion: Volume % FF Base −0.3 Gasoline Yield:Volume % Base +1.3 Total C3 plus C4 Yield: Volume % FF Base −1.6 Ethaneand Lighter Yield: Weight % FF Base −0.2 Coke Yield: Weight % FF Base+0.07

EXAMPLE 5 Ability to Sample Multiple Points in the FCC Unit

The FCC reaction effluent sampling technique is called Reaction MixSampling (RMS). One key advantage of RMS testing is that the techniquehas now been adapted for collection of reaction mixture or vapor streamsamples from points in the reactor other than the overhead line.

When collecting effluent sample from the reactor overhead line to thefractionator, the probe is open on the sampling end because the reactioneffluent has already been disengaged from the catalyst via the risertermination device and the reactor cyclones. However, the RMS sampleprobe is now fabricated so that a sintered metal filter can be installedon the collection end of the probe. This allows for samples to becollected from areas of high catalyst density such as the FCC riser,reactor and stripper. Described below are series of alternate RMSsampling positions and the purpose for collecting RMS vapor samples fromeach.

1. Riser at multiple elevations above the feed injection point tomonitor the extent of reaction as the oil/catalyst mixture flowed up theriser and to explore the impact of reaction contact time.

2. Outlet of the riser to determine the cracking yields before theeffects of any thermal cracking that would take place in the reactorvessel.

3. Outlet of the riser termination device.

4. Simultaneously, the riser outlet and the reactor effluent line todetermine the degree of conversion and thermal cracking that occurs inthe reactor vessel.

5. Riser at multiple points across the diameter to explore theconsistency of oil/catalyst distribution above the feed injectors.

6. Riser at the transition from horizontal to vertical flow to explorethe impact of the transition on oil/catalyst distribution.

7. Catalyst stripper bed and stripper transition into the spent catalyststandpipe to determine stripper vapor composition and explore strippingefficiency.

EXAMPLE 6

Currently, refiners are particularly interested in exploring FCCcatalyst stripping efficiency. The RMS sampling technique has been usedto extract vapor samples from the stripper bed and the transition fromthe stripper into the spent catalyst standpipe. Presented in Table 3 areresults from RMS sampling of three strippers. One of these stripers wasoperating very poorly and one of them was operating very efficiently.

TABLE 3 FCC Stripper Outlet RMS Vapor Composition FCC Catalyst StripperUnit A Unit B Unit C Total Water in RMS Sample: Wt %   35%   84% 91.5% Total Hydrocarbon in RMS Sample: Wt %   65%   16% 8.5% Gasoline in RMSSample: Wt % 23.8% 0.08% 0.9% 650 F. + Bottoms in RMS Sample: Wt %  6.1%0.04% 1.8% Ethane + Lighter in RMS Sample: Wt % 11.2% 14.8% 2.8%

This data can then be used in conjunction with an engineeringcalculation to estimate the amount of hydrocarbon flowing from thestripper to the regenerator. More importantly, the stripper vaporcomposition provides significant clues as to what is going on in thestripper. The first critical factor is the percentages of water andtotal hydrocarbon in the recovered vapor stream. Obviously, as stripperefficiency increases, the percentage of water in the stripper vaporsample will increase as well.

The second critical factor is the distribution of hydrocarbon in the RMSsample. There are basically three sources of hydrocarbon into the FCCstripper.

1. Reaction effluent in the interstitial spaces between catalysts.

2. Reaction effluent in the pores of the catalyst.

3. Unreacted (and unvaporized) oil on the catalyst surface and in thecatalyst pore.

If the stripper outlet vapor contains more than a very small percentageof gasoline on a total sample weight basis, then it is likely that allof the reaction effluent trapped with catalyst does not disengage andflow upward into the reactor. For example, the Unit A stripper vaporsample contained 24% by weight gasoline. This stripper had no internalsof any type and it was clear that some significant portion of reactioneffluent flowing to the stripper was reaching the regenerator. At theopposite end of the spectrum, Unit C contained only 0.9 weight %gasoline in the stripper vapor, which probably represents reactioneffluent diffused out of the catalyst pores.

Another critical factor in reviewing stripper results is the content ofethane and lighter gas in the stripper vapor. The production of lightgases in FCC, especially methane and hydrogen, is recognized as aby-product of thermal cracking. For these samples, the weight percentageof sample consisting of ethane and lighter gas ranged from a low of 2.8weight % to a high of 14.8 weight %. The production of light gases inthe FCC stripper is believed to result from the thermal decomposition ofheavy unvaporized hydrocarbon molecules on the surface of the catalystalong with condensation and polymerization of multi-ring aromatics. Highlevels of light gas in the absence of C5+ hydrocarbon in the FCCstripper effluent may actually indicate a problem with the poor feedatomization and vaporization, not a stripper mechanical problem. If anoil molecule will not vaporize in the presence of 1250° F.+ catalyst atthe bottom of the riser, it will certainly not vaporize in an FCCstripper at 960° F. to 980° F.

EXAMPLE 7 FCC Model Tuning and LP Update

Several refineries use an FCC process model to determine optimumoperating parameters to maximize profitability and push the unit tomultiple constraints. Typical process variables include feed rate,reactor temperature, feed preheat and catalyst activity. The ability ofany model to estimate these optimum conditions is contingent upon itsability to accurately predict the true process response. Most modelswill allow the user to adjust “tuning” factors to match the modelresponse with commercial data.

Unit technology will play a major role in determine yield shiftsassociated with process changes. A unit with a poor stripper such asunit A above, will have a very different response due to feed preheatchangers than a unit with a modern stripper such as unit C. This is dueto the effect of entrained hydrocarbon on delta coke with changers incatalyst circulation. Another example is reactor temperature. Modernrise termination devices have reduced the post-riser contact time andminimized secondary reactions changing the yield response to processvariables. FIG. 1 shows this effect for a modern reactor system. Thedefault model was tuned to an open riser termination design thatexhibited gasoline overcracking with increasing reactor temperature. Themodern design exhibited less overcracking. The model was tuned to matchthe commercial data and provide greater confidence in optimizing unitprofitability.

FIG. 3 shows a FCC Model Tuning with RMS data. Another applicationrequiring accurate prediction of process variable effects is therefinery linear program (LP). Most refineries will use the LP to setglobal operating conditions for the FCC with the process model used todetermine location optimums. The LP is also used to evaluate differentcrudes and feed streams. If the vectors in the LP do not accuratelyreflect the process, poor economics decisions may be made.

EXAMPLE 8 FCC Revamp Audit

Driven by the evolutionary nature of FCC process technology, refinersare continually assessing the performance of the FCC and contemplatingimplementation of the latest developments. FCC reaction effluent testingcan play a major role in an FCC revamp analysis study. Reaction effluenttesting represents a convenient method for developing the FCC baseoperating case data by isolating the reactor section yields. This isespecially important when modifications are anticipated for the FCCproduct recovery section. Further, only reaction effluent testing issuitable for exploring conditions at various points in the FCC reactionsection where catalyst is present.

One recent revamp study was undertaken to determine the impact ofupgrading riser termination to one of the advanced designs available.Reaction effluent testing was performed just before and right aftercompletion of the revamp. Careful planning was undertaken to insure thatthere were minimal differences in feed quality between the two runs. Keyresults from the two test runs are presented in Table 4. These resultsindicate that there was significant yield benefit achieved with therevamp.

TABLE 4 FCC Revamp Audit Results FCC Case Pre-Revamp Post-Revamp RiserOutlet Temperature: F. Base +2 Catalyst MAT Base +2 Unit Conversion:Volume % FF Base −0.4 Gasoline Yield: Volume % Base +3.8 Total C3 plusC4 Yield: Volume % FF Base −3.0 Ethane and Lighter Yield: Weight % FFBase −0.13 Hydrogen Yield: Weight % FF Base −0.03 Coke Yield: Weight %FF Base −0.18

Accurate yield determination and process variable response are criticalto FCC unit optimization. Reaction Mix Sampling is an efficient tool todefine these parameters. The results can be used to tune the FCC processmodel, update LP vectors, audit revamp or catalyst changes and determineoptimum process conditions to maximize unit profitability at multipleconstraints.

Modifications

Specific compositions, methods, or embodiments discussed are intended tobe only illustrative of the invention disclosed by this specification.Variation on these compositions, methods, or embodiments are readilyapparent to a person of skill in the art based upon the teachings ofthis specification and are therefore intended to be included as part ofthe inventions disclosed herein.

The above detailed description of the present invention is given forexplanatory purposes. It will be apparent to those skilled in the artthat numerous changes and modifications can be made without departingfrom the scope of the invention. Accordingly, the whole of the foregoingdescription is to be construed in an illustrative and not a limitativesense, the scope of the invention being defined solely by the appendedclaims.

1. A process for controlling on line FCC effluent exhibiting asorptionin the near infrared (NIR) region comprising: a) measuring absorbancesof the effluent using an NIR spectrometer measuring absorbances atwavelengths within the range of about 780-4000 nm, and outputting anemitted signal indicative of said absorbance; b) subjecting the NIRspectrometer signal to a mathematical treatment (e.g. derivative,smooth, baseline correction) of the emitted signal; c) processing theemitted signal or the mathematical treatment using a defined model todetermine the chemical or physical properties of the effluent andoutputting a processed signal; and d) controlling on-line in response tothe processed signal, at least one parameter of an FCC processgenerating the effluent.
 2. The process of claim 1 including the step ofusing NIR measuring on line to control reaction mixing sampling (RMS) online.
 3. The process of claim 2 wherein the NIR measuring of RMSprovides near instantaneous prediction of FCC unit yields.
 4. Theprocess of claim 2 wherein the NIR measuring of RMS verifies FCC feedquality.
 5. The process of claim 1 including the step of using NIRmeasuring on line of reaction effluent to control riser outlettemperature on FCC processing yields.
 6. The process of claim 1including the step of using NIR measuring of reaction effluent tocontrol riser lift velocity.
 7. The process of claim 1 including thestep of using NIR measuring on line of reactor effluent to control riserlift steam rates to control FCC product yields.
 8. The process of claim1 including the step of using NIR measuring of reaction effluent tocontrol riser lift velocity.
 9. The process of claim 1 including thestep of using NIR measuring on line of reactor stripper effluent tocontrol FCC catalyst stripping.
 10. The process of claim 1 including thestep of using NIR measuring of reaction effluent to provide on-linemodeling of FCC processing.
 11. The process of claim 1 wherein saidabsorbances are measured at wavelengths within the range of about780-2500 nm.
 12. The process of claim 1 wherein said absorbances aremeasured at wavelengths within the range of 1100-2200 nm.
 13. Theprocess of claim 1 wherein said absorbance is measured in at least onewavelength and includes the steps of: a) periodically or continuouslyoutputting a periodic or continuous signal indicative of the intensityof said absorbance in said wavelength, or wavelengths in said two ormore bands or a combination of mathematical functions thereof, b)mathematically converting the signal to an output signal indicative ofthe mathematical function; and controlling the FCC process on-line inresponse to the output signal.
 14. The process of claim 1 wherein thestep of controlling on-line allows for real time optimizationprocessing.
 15. The process of claim 1 including the steps of: obtaininga first data set of NIR spectroscopic data samples by subjecting theeffluent to NIR spectroscopy; generating a second data set of NIRspectroscopic data samples by processing the first data set using asecond technique; identifying a component of the effluent by performinga NIR analysis on the second data set; and controlling the FCC processon-line in response thereto.
 16. The process of claim 1 including thestep of: mathematically converting the signal to an output signalindicative of the parameter.
 17. The process of claim 7 including thesteps of: periodically or continuously outputting a periodic orcontinuous signal indicative of the intensity of the NIR absorbance inthe wavelength, or wavelengths in the two or more bands or a combinationof mathematical functions thereof, mathematically converting said signalto an output signal indicative of the mathematical function; andcontrolling on-line in response thereto.
 18. The process of claim 1including the step of using the NIR results in FCC simulation softwareto control on-line unit yields and qualities.
 19. The process of claim 1which allows sampling of various locations in the reactor such ascatalyst stripper vapor, reactor dilute vapor, riser vapor and reactoreffluent to quantify yields and optimize the process.
 20. The process ofclaim 1 which allows an audit of a process or mechanical change on theunit to quantify the magnitude of the change on yields, performance andeconomics.
 21. The process of claim 1 including the step of using NIRmeasuring on-line of reactor dilute vapors to control riser outletconditions and vapor quench.
 22. The process of claim 3 where yields areused to tune an FCC simulation model and benchmark LP predicted yields.